Resistor Color Codes

Resistor values are coded with colored bands painted onto the shell of the resistor. To read the value of the resistor, you need to know what the colored bands mean, and you need to know from which end to start reading.

Which End to Start Reading From

Most resistors will have four colored bands. Three of the bands are used to indicate the resistance value and the fourth indicates the tolerance of the part. Some resistors will have five colored bands. In these cases the first four indicate the resistance value and the last one is the tolerance band.

In either case, you need to seperate the tolerance band from the resistance bands. The tolerance band will usually either be gold or silver, or it will be seperated from the other bands by a larger space than the rest.

Once you've identified the tolerance band, start reading the resistance bands from the other end of the resistor.

The tolerance band in this picture is gold. To read the resistance, start from the other end, in this case the brown band.

Interpretting the Resistance Bands

Consult the chart below to determine what each band means. This chart applies only to the resistance bands, not the tolerance band.

In the picture above, the first band is brown, so the first significant digit is one. The second band is black, so the second significant digit is zero. The third band is yellow, so the multiplier is x10K. A one followed by a zero multiplied by 10K is 100K.

	BLK	BRN	RED	ORA	YEL	GRN	BLU	PUR	GRY	WHT
1st & 2nd bands	0	1	2	3	4	5	6	7	8	9
3rd band	x1	x10	x100	x1K	x10K	x100K	x1M	x10M	n/a	n/a

Another way to read the chart if the multiplier is confusing is to think of the third band as the number of zeros to tack onto the first and second significant digits. For instance, brown, black yellow means a one (brown), followed by a zero (black), followed by four more zeros (yellow). Therefore, brown, black, yellow is a one, a zero and four more zeros or 100,000 or 100K.

Interpretting the Tolerance Band

Most resistors will have a gold or silver tolerance band. Gold means 5% and silver means 10% tolerance. Parts with higher precision will have a colored band that is easily confused with the resistance band. If this is the case, the tolerance band is usually offset from the resistance bands by a larger space. The hobbyist will seldom deal with these higher precision parts, however.

	BRN	RED	GRN	BLU	PUR	GRY	GLD	SLV
Tolerance Band	+/- 1%	+/- 2%	+/- 0.5%	+/- 0.25%	+/- 0.1%	+/- 0.05%	+/- 5%	+/- 10%